What is the pH of a 0.30 M solution of HCN at 25oC (For HCN, Ka = 4.9 x 10-10)  

What molar ratio of acetic acid to sodium acetate is required to create a buffer solution having a pH of 4.94 at 25°C? Ka for HC2H3O2 is 1.8 × 10–5.

Consider the Ka values for the following acids: Cyanic acid, HOCN, 3.5 × 10–4Formic acid, HCHO2, 1.7 × 10–4Lactic acid, HC3H5O3, 1.3 × 10–4Propionic acid, HC3H5O2, 1.3 × 10–5 Benzoic acid, HC7H5O2, 6.3 × 10–5 Given initially equimolar solutions of each weak acid, which solution will have the lowest pH once equilibrium is established?

Using the chemical equilibria below,   N2(g) + O2(g)   ⇌  2 NO(g) K1   N2(g) + 3 H2(g)  ⇌   2 NH3(g) K2   H2(g) + 1/2 O2(g)   ⇌  H2O(g) K3 Determine the method used to calculate the equilibrium constant for the reaction shown below.   4 NH3(g) + 5 O2(g)  ⇌   4 NO(g) + 6 H2O(g) Kc  

What is the energy change (in J) when the temperature of grams of Xenon (C = 1.03 J/g°C) is decreased from  °C to  °C (Report your answer to 2 decimal places, i.e. xx.xx and make sure to include a negative sign, if necessary.) (No units are necessary in answer.)

Which of the following expressions represents a proper expression for the rate of this reaction?    F + 2G → 2A + 3B  (Select all that apply.)

Consider the following molecules: ethanol (CH3CH2OH), acetic acid (CH3COOH), and dimethyl ether(CH3OCH3).  Which of these molecules is/are expected to form hydrogen bonds? Check all that apply.

Calculate the energy in the form of heat (in J) required to convert grams of liquid water at °C to steam at °C. Assume that no energy in the form of heat is transferred to the environment. (Heat of fusion = 333 J/g; heat of vaporization = 2256 J/g; specific heat capacities: liquid water = 4.184 J/g⋅K, steam = 1.92 J/g⋅K; water’s normal melting point is 0°C and normal boiling point is 100°C) (Report your answer in Joules, with 1 decimal place, i.e. xxx.x)  (No units are necessary in answer.)

A sample of methane, CH4, occupies a volume of mL at 25°C and exerts a pressure of 1115.0 mmHg. If the volume of the gas is allowed to expand to mL at 298 K, what will be the pressure of the gas (in mmHg)? (Report your answer in mmHg to 1 decimal place, i.e. xxx.x) (No units are necessary in answer.)

Evaluate or determine that the limit does not exist for each of the limits.